Automatic cut-off valve for vacuum pipe lines



may 27,1924,v I 1,495,495

. J. H. NAYLOR AUTOMATIC CUT-OFF VALVE FOR VACUUM PIPE LINES Filed Oct. 2l 1922 FIL?. 3 /Jf Patented May 27, 1924.

@MTE

AUTOMATIC cT-orr 'vAnvE FORVCUU'M'PIPE LINES.

applicati@ fiied-ocfoter 21, 'lata serial Nb. 595,926.

To all whom t may concern.' O Be it known c that I, JAMES HENRY NAYLOR, a subject of the King, of -Great Britain, residing at Renall Street, Masterton, New Zealand, have invented newV and useful Improvements in AutomaticYQu't-YO Valves for Vacuum Pipe Lines, of which the following is a specication. K

The object of thepresentjnvention isgto provide anv improved construction of lvalve for interposition within a vacuum-pipe line, in order to allow for the automatic closing of such line against the entry of anexcess of air Should the vacuum prevailing in the line be reduced below a' fiXednor'mal degrec. My invention is offparticular use in milking machine installations ofY the class in which 'teat cups are connected by Y a b-ranch pipe line with Va vacuum main to draw the milk from "the .teats and convey it through such branchto the/'milk receiver. These teat cupsinl use are liable-toy drop from the teats so that 'there 'is a large'ginrush of air thatdestroys the vacuumfin the system. lf vother cows are being, I'nilked at the same time thegteat cups thereonnthen lose their grip and also 'dropoQ withthe result that theV whole installation is "pnt out of working` orden-andthe teat'cnps are liable to. become dirtiedby A,dropping onto the `floor and any'loosedirtg-is liable'gto be drawn in through-them, into the system,

contaminating the milk.

The cut on devised, in its 'application to such va milking system, has Ibeen designedto Vbe arranged at any convenient positin vin thelteatk cup branch, but 'preferably't'one-for adjacent to the usual clawto which the four teatcups of each setV are connected,

land it operates in suchagway as to keep the Vway through' such branch iilly open, iso

long as the vacuum inthe connections is Vmantaled', but immediat'elythel vacuum t,is

destroyed by the entry 'of'air 'into one -or more of the tea-t cups, it closes thezbran'ch thus ,sealing it against the continued infiow of a'ir Ato destroy the' vacuum'of'the system.

'My vinvention therefore consists Vin a construction of valve that embodies within: it a valve plunger adapted to openY or 'close 'the connections'of the teat cups with thebranch,

'p that is kept open by the action of yatmoslpheric lpressure acting on one 'endthereof, while vacuum prevails'at the. otherifend, and which 'is controlled 'by rvmechanical or other means 'such that when the vacuuml is destr oyedJ and Y.the air 1 pressiire balanced, the plunger is movedto shutoff such 'connections fromz that particular branch. In, the accompanyingv drawings lthree Vembodiments "ofl invention are shov'v-n,4 in twoof whichn the. plunger is controlledby means Soia spring ,contained` within the valve, TYwliileili-the Ytlii i?d, ilt is `controlled byL-.ajbye pass connection with the vacuum mam' ln theV drawingsff. l Y Figure lis anpelevation of va spring-con trolled valve Vadapted to beinterposed withinifthe vauumfbranehv--1ne Fgure? is aplanfthi-eolf Y A. Vliligure B Y- is l,ayfsectional elevation showins-fthe valve. penfl Figuref` isA a similar view showing the valvejclosed. l. ,y ,j 4 ,Fi-gurefs a sectional. elevati@ 0f f1 'Valve constructed :for 'vacuumcontrol rFigure(iis/a longitudinal section'rof the Spring-Optrolleaivalve- @Hibodd therein Accjordingvpto Figures l` tonhthe valve Alng .nnpl tlibularibranchesB and B openma imm-'lit gatpoints f-diametrially ,oppor site oneqjano/ther.andgat a `suitable distance brncszbxtend,inrgthesame line and form themk waythmughjthevalve- They are Kadapted to ,be .connected respectively with the broken endsof'the milking branch from the v vacui11if1- main.

The gpm an i ai@ @naar ,Aas

jclasedwhle .its lowerfenzl is Opened and i s.formed at alshort distance in vfrom4 the vend,-vvithffa va'lvcgseat C.A A screwcap D vlua-ving' ;a; large' central .Opening iSv Provided., Aand 1s screwed over the open lower end o1p l Vthefcylinder AV to retain the plunger valve 'in fplace within the cylinder.

,"{Theplunger valve is lformed by a stem 'Erha'vingfacircular flat valve head. F iXed end'of the -casing and isv 'designed to fit fromlbeneathfupon the valve seat C so as yto sealY the`v pen-in'ginto Ythe, upper ypart of -the casing. :The-piston Gis'fmadeof such a lengththat itv'isgcapab'le of extending across lthe openings 'into ythe branches B and B when moved in, while the several parts of the casing and of the plunger are made ot' such relative sizes that the piston G may rise in the casing above the level of the branch openings and when in this position. the valve head F will engage the seat C, as shown in Figure 3. When the plunger is pushed down to cause the valve head F to engage the cap D, the piston Gr will occupy a position closing the branch openings, as shown in Figure 4f.

Fitted into the top of the hollow piston G. is a guide formed by an inverted cup H which may have an upwardly projecting central stem H that passes out through the closed top of the casing. Arranged in the space between the top or" the guide and the bottom of the piston, is the helical spring J which is placed in compression and has a normal tendency to expand and push the piston down to its lower position.

rlhe strength of the spring J is so arranged relatively to the surface area of the valve head F that it will be overcome by the atmospheric pressure acting on the outer face of said valve head when a vacuum prevails in thel branches B and B and in the casing A, so that such air pressure will then push the plunger up to the position shown in Figure 3 and maintain it there in order that milking may proceed. When however the vacuum is broken by the entry of air and suficient air enters the casing A, that, together with the springs energy will overcome the outside atmospheric pressure, and the spring J will act and force the plunger down to the position shewn in Figure t, to close the main way against the passage ot air into it. The valve may thus be regulated to close automatically immediately the degree of vacuum in the connections Jfalls below a certain fixed degree, by regulating the strength of the spring J.

When the valve is to be opened again, the operator may press with his finger on the valve head F and litt the plunger until it raises the piston G suiiciently to connect the casing A with the branches B, B', when if a vacuum prevails in such branches, the air pressure will be free to act upon the head F and raise the plunger to its full eX- tent. If it is desired to close the valve mechanically for any purpose the stem H of the guide H when such is provided will be pressed on by the operators finger whereby the guide and plunger will be forced down together.

In the form of valve shown in Figure 5 designed tor vacuum control of the plungers movement to shut off the branches, the cap D is made with a central nipple extension D that is connected with the vacuum main and the stem E of the plunger is extended below the valve head F (which in this case is formed as a hollow piston) neatly fitting within the nipple. The spring J is omitted and the stem E is extended above the top of the piston G so as to project through the top of the casing and its upper end is broadened.

Jatmospheric Vpressure acts on the underside of the piston F so that while a vacuum remains within the casing A, the plunger will be forced to the top end of the casing clear of the branches B and B. Should the acuum be destroyed the pressure on both sides of the hollow pistons will be the same, when by reason of the atmospheric pressure acting on the top area oi the stem E, and its bottom area being in vacuum, the plunger will be forced down to its lower position to close the branches B, B.

rlhe construction shown in Figure 6 provides for the milk tube K of the ordinary teat cup claw acting as the casing for the plunger valve. rllhis casing is formed with the usual ports M connecting with the cross tubes M to which the teat cups are con nected in the well known manner. The back end of the tube is left open and a long sleeve N is fitted into such end and adapted to slide to and fro therein. This sleeve is closed at its outer end and open at its inner end so that atmospheric pressure will act on the outside of the head thus formed, while the inside will be subject to the vacuum prevailing inthe tube K. rlhe sleeve is formed with two ports N in it that are adapted at one limit of the sleeves movement to be brought into register respectively with the ports M of the milk tube and thereb open up the branches M to such tube, an to be moved away so that solid portions of the sleeve will extend across and close the ports M at the other limit of the sleeves movement. llhese movements are limited by the pin O screwed into the sleeve N and passing through a longitudinal slot O in the tube Fl.

A helical spring J is arranged around the outside of the outer sleeve end and is confined between such end and a collar 7c on the end of the milk tube. This spring is in compression such as to normally force the sleeve outward to the second of the positions mentioned, but is overcome by the atmospheric pressure on the end of the sleeve when a vacuum prevails within the tube 7c, so that the sleeve is forced in to the first of the mentioned positions and retained there. When the vacuum is destroyed or decreased in degree to the required extent, the spring will act and Jforce the sleeve out to close the branches lv" from the pipe line, in the manner required.

l claim l. n combination with a vacuum pipe line, an automatic cut ofiq valve comprising .a cylindrical casing open at one end and closed at the other end and provided 'ith connections to said pipe line and a plunger valve movably fitted in the said casing, at

one limit of its movements cutting off communication with the said pipe line, at the other limit opening communication therewith, the said plunger valve being continuously exposed to atmospheric 'pressure at its one end and to the vacuum prevailing in the said pipe line at its other end, and means for moving the said plunger valve to the cut off position upon the air pressures on its two ends being about balanced.

2. In combination with a vacuum pipe line, an automatic cut off valve comprising a cylindrical casing open at one end and closed at the other end and provided with connections to said pipe line and a plunger valve movably fitted in the said casing, at one limit of its movements cutting off communication with the said pipe line, at the other limit opening communication therewith, the said plunger valve being continun ously exposed to atmospheric pressure at its one end and to the vacuum prevailing in the said pipe line at its other end, and a spring acting on the said plunger valve tending to move it to its cut oil position.

3. In combination with a vacuum pipe line, an automatic cut oft1 valve'comprising a cylindrical casing open at one end and closed at the other endand having connections to said pipe line, and a plunger valve movably tted Vin said casing, at one limit of its movements cutting of communication with the said pipe line and at the other limit opening communication therewith, a valve head on the end of the said plunger valve adjacent to the open end of the said casing and exposed to atmospheric pressure on its outside and to the Vacuum prevailing in said pipe line on its inside, and a spring acting on the other end of said plunger valve tending to force the said valve head into the open end of the said casing upon the air pressures on the two sides of the said valve head being about balanced.

4. The combination as set forth in claim 3, comprising a presser cap provided between the closed end of the said casing and the adjacent end of the said plunger valve and enclosing the said spring,and a stem extending from the said cap outwards through the closed end of the said casing.

In testimony whereof, Iv afx my signature.

J. H. NAYLOR. 

